In organic lab this week we were mixing (1-R, 2-S) ephedrine with mandelic acid to get crystals. I dissolved both compounds in 6 mL 95% EtOH and then poured them together. After cooling + glass prodding I should have had no trouble getting crystals. HOWEVER, during the cooling I accidently added about 10 mL of methylene chloride to the mixture, and was unable to get crystals at room temp. I knew DCM has a low boiling point so I just boiled off all of the solvent and added 12 mL of EtOH 95%. I then re-heated the soln and let it cool. I prodded the sides with a glass rod and still nothing. Then I decided to put the soln (it was in a 100 ml erlenmeyer) on ice. Before you know it I had crystals. Can I be confident that these are the crystals of the resulting compound when ephedrine and mandelic acid are reacted? Once I got crystals I stored them in my drawer for next week at room temp. It seems nobody else needed ice, so i'm worried that everything will be redissolved when I get back. Thanks.